Here are details pulled from 2 images in Eric's (ebrandt78's) Flickr set (images link to the complete photos; the entire set is worth a look):

South Piers (looking approximately south-southeast from the north shore). The piers (tops marked by red arrows) appear substantially unchanged. The trusses appear to have walked off the piers to the left (west).
North Piers (viewpoint is from downstream-- east-- on the north side of the river). The north piers tilt noticably to the south. (The western pier is mostly obscured by the eastern one. A part is just visible to the right.) The decking to the north (right) tilted northward, exposing the trusses (see SDB's first photo), which could have created a twisting torque before the attachments broke loose.


Cause or effect?
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UPDATE 070807 19:36: NTSB Chairman on the investigation, below...

NTSB Details Investigation Process:

[National Transportation Safety Board Chairman Mark] Rosenker said the investigators spent Friday focusing on the southern part of the bridge...

"We noticed that the section of this part of the bridge behaved differently in the video and in the way it sat in the final collapse."

He said that the top section of the bridge shifted 50 feet to the east and the structural part fell a bit west. The rest of the bridge collapsed in place.

"We believe that as the bridge began to fall it shifted and that's all I am saying," said Rosenker, adding "When you compare it to the rest of the bridge which appeared to collapse in place."
...
He refused to elaborate saying to do so would be to begin analyzing the cause...

He said looking at the debris and structure of southern end, a failure at the northern end could transfer loads to the southern end and trigger the collapse. "So, we don't have an answer, we have a starting point..."

Posted by: Old Grouch in Linkage at 22:11:07 GMT | No Comments | Add Comment
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